Gauge glass



Dec. 15, 1936. H. E. BRELSFORD GAUGE G LAS S Filed June 20, 1932 2 Sheets-Sheet l 3mm l/arr 5 Patented Dec. 15, 1936 UNITED STATES GAUGE GLASS H Harry E. Brelsford, Birmingham, Mich assignorto Diamond Power Specialty Corporation,

Detroit, Mich., a corporation or Michigan Application Jnne 20, 1932, Serial No. 618,366

I 11 Claims.

ber through'which the level of the fluid being measured may be observed, which transparent member will be exposed to the temperature 'of the fluid being measured, and to provide means acting counter tothis temperature and tending to maintain the transparent member at a predetermined desired temperature.

The invention further contemplates the provision of a gauge of the above mentioned character provided with means for preventing damage or injury to operators in the event that the gauge becomes broken.

Still further the invention contemplates the provision of an alarm or indicating means associated with a gauge for advising an attendant of leakage or failure of the gauge.

'The invention further contemplates the provision of means for exerting a counter pressure on a transparent member through which a fluid under high pressure may be observed to thus prevent this transparent member from becoming broken by the pressure of the fluid being meas- 35 ured.

Still further the invention contemplates the provision of a gauge of the above mentioned character in which the transparent member will be capable of withstanding extremely high term 40 peratures so that the gauge may be readily utilized under conditionsvwhere gauges of this character have heretofore not been practical.

The invention further. contemplates the provision of means for heating or cooling a gauge 45 of the above mentioned character, whenever this becomes desirableto obtain a proper indication of the level of 'the'fluidbeing measured. J V

Numerous other objectsand advantages of this invention will become more apparent as the following description'prooeeds, particularly when reference is had to ings, wherein:

. Fig. l is a diagrammatic viewvof a tank or-the like containing a'fluid, the level of which is to ,onthelinel6ofFig.2.

oil and the like.

the accompanying draw-' be measured, together with a gauge constmcted in accordance with. the teachings of this lnven-' tion associated with this tank; I

'Fig. 2 is anelevational view partly in section a of the gauge shown in Fig. 1; a

Fig. 3 isasectional view taken substantia on the line H'of Fig. 2 a 3 Fig.- 4- is a fragmentary perspective view "of I a portion of the gauge;

Fig. 5 is a diagrammatic view showing the manner in which an alarmmay be electrically 1o associated with a gauge constructed in accord ance with the teachings'of the invention; and

Fig. 6is a sectional view taken substantially- Referring then particularly to' the drawings "16 wherein like reference characters-designate corresponding parts throughout all views, the numeral l0 designates a flat gauge/body having an internal longitudinally extending openingor cavity ll for the receptlon g'ofth'e fluidfto'be 2o measured. Conduits 'IZ and*--l l* arej connected to the upper and lower ends-respectively of the. a cavity ii, and these conduits'f'are in communication with the interior of the tank or container it above and below the level of the fluid therein. Valves I! and it are mounted inthe conduits l2 and I3, respectively, to providefor clos ing communication between the interior of the tank andthe gauge.

It is to be understood that the tank." may constitute any container adapted to receive a quantity of a fluid. This tank may be a boiler drum or the like or maybe atank such, for example, as is usedin the hydrogenation of crude The body II is providedon "its, opposite side faces with recesses 20 v.p'rovidir'ig sea'ts j for receiving projections 2| winter-mediate cover members 22. The body portion is'also provided on each-side face with projections 23" arranged 4 to engage in recesses 24 in the adjacent faces of the intermediate covers 22 to prevent rela-f tive sidewise movement betweenthe body II and these intermediate covers. Since the intermedi ate covers are of iikeconstruction, one only will be described in deta'il,it being understood that the complete gauge is symmetrical on opposite sides of a center line passing through the gauge body orholrler ll. Each projection .Ii surrounds a 5 member 25. which is. arranged in a recess I l formed in the. cover 22.. This recess may, if desired,'be provided at longitudinally spacedpoints with shoulders 21 forming seats for the trans-.

, parent member or sight glass; 'lnusitwill be.

apparent that the transparent member is spaced for part of its length from the surfaces 28 of the recess, there being preferably, however, a bead 29 which borders the recess adjacent the outer free edge thereof and engages the sight glass adjacent its outer free edge.

It will be noted that the cavity l l in the body In opens through the sides of the body and thus through the floors of the seats 20. For closing or sealing this cavity there is provideda transparent strip 30 preferably of mica which fills the seat and isdisposed between the projection 2| and the body l0. Gaskets like are preferably positioned between the mica strip and the body. 10, these gaskets extending the full length of the seat 20 but being of such a width that they do not extend over the sight glass 25. i

The sight glass is preferably of slightly less thickness than the depth of the recess 26, with the result that the projection 2| acts directly on the mica strip, and urging this strip against the gaskets 3i, seals the cavity l I in the body 10. The pressure of the fluid in the. cavity II is exerted on the mica strip,-and this strip is backed up and thus prevented from breaking by the transparent member or sight glass 25. Itwill be apparent, however, that the clamping action is between theprojection 2| and -the body l0 so that the transparent member is free to expand and contract except for the strain imposed upon it by friction of the mica strip against the face of this transparent member. For the purpose of effectingthis clamping action between the projection and the body l0, bolts 32 extend through the several covers and body of thegauge, these bolts being engaged by suitable clamping nuts 33, as clearly illustrated in Fig. 3 of the drawings.

Each intermediate cover 22 is provided with a longitudinally extending cavity 35. This cavity does not, however, extend the full length of the member 22, there being provided laterally extending bores 36 at the ends of the cavity into which conduits 31 and .38 are lower endsof the cavity respectively. A separate pair of conduits, 31 and 38, is provided for the cavity 35 of each intermediate cover 22' on opposite sides of the gauge body Ill.

The cavity 35 opens at its one side into the recess 26 so that fluid admitted to the cavity may flow into this recess between shoulders 21 and thus partially around the sight .glass disposed in this recess. This fluid will, however, be prevented from passing into cavity II in body 10 by virtue 0f the mica strip 30 sealing this latter cavity.

Each intermediatemember 22 is provided on its side opposite the sidein which the recess 26 is located, with a recess or seat 40 adapted to receive a projection 4| on an outer cover member 1 42. The projection 41 of this cover member surrounds a transparent member or-sight glass 43 which is disposed in-a recess 44 formed in thecover member. If desired, the transparent member 43 might be mounted looselyin the same manner as the transparent member'25, but since this latter member will not in'general be subjected to pressures and temperatures as great as the member 25, it may be clamped in position by providing gaskets 45 and 46 of asbestosor the like, these gaskets being disposed between the projection 4i and the transparent member 43 and the seat 40 and between the otherface of the glass and the base of the recess 44. ,Thus when the nuts 33 are tightened on the clamping bolts 3| of asbestos or the tapped at the upper and the glass 43 will be clamped in position to effectively seal the outer side of the cavity 35.

Located in the conduit 38 is a check valve 50 arranged to permit the flow of a fluid into the cavity 35 of the associated intermediate cover 22, but designed to close in the event that the pressure in the cavity reaches a predetermined degree. A spring 51 preferably holds the check valve 50 away from its seat 52, the valve at this time being held against a cage or the like formed in the conduit. The conduit is also proferably provided with a manually controlled valve 54 by which the flow of fluid into the cavity may be regulated.

The conduit 31 is provided with a check valve 55 arranged to engage a seat 56 and normally held away from this seat by a spring 51 whereby fluid under a predetermined low pressure may flow from the cavity 35 by way of conduit 31. A cage or the like 58 is provided for receiving the ball check valve when the latter is in open position, and the conduit 31 may, as illustrated, be

to discharge into a funnel or the like-6U formed on the upper end of a discharge conduit 6| which may conduct the fluid discharged from the cavity by way of conduit31 to any desired point. It will be apparent that if the discharge end of conduit 31 is spaced above funnel 60 the discharge from this conduit may be at all times observed.

It'constitutes a feature of this invention to place a pressure gauge in communication with the chamber or cavity 35, and while this pressure gauge may be tapped into this cavity at any desired point, it is shown as being tapped into the conduit 31 in advance of the check valve 55. Thus there is provided a short pipe section which is tapped into the conduit 31 and which communicates with a pressure gauge 66 of any desired character. This pressure gauge is preferably provided with a suitable pointer or the like (not shown) by which the pressure of the fluid circuit 61 in which there is electrically connected a. suitable alarm such as a bell or the like 68,

and this circuit is arranged to be closed when the pressure in cavity 35 reaches a predetermined degree, this being accomplished by providing a contact member 69 connected to the plunger or pressure actuated member 10 of the gauge 66. It will be obvious that the electrical circuit 61 may be connected to the pressure gauge 66 as shown or may be directly controlled by a diaphragm or the like exposed to the pressure in cavity 35. i

It will benoted that each member 42 is provided with a longitudinally extending slot 1| which opens through to the recess 44. This slot is outwardly flared to facilitate viewing the liquid often in the neighborhood of 1000 F. or more 7.

with pressure in the neighborhood of 1000 lbs per' sq. in or more.

these high temperatures and pressures. The present invention provides cooling means for use with the sight glasses and gauges for determining liquid levels under temperatures and pressures as high as these and contempates further that if the cooling means is not sufllciently efficient to effect the desired cooling of the sight' glasses, these may be made of quartz which has a critical temperature in the neighborhood of 1900 to 2000 F.

It will be noted that the several parts of the gauge are clampingly engagedwith each'other only at the points where the projections 4| and 2| engage in their respective seats; Thus the several cavities or openings in the gauge parts may be eflectively sealed upon tightening of the nuts 33 on the clamping bolts 32.

In use, the gauge may be connected to a tank or the like in the manner illustrated in Fig. 1 of the drawings. The fluid or liquid the level of which is to be determined will enter cavity II by way of conduit I3, the pressure in this cavity being uniform throughout by virtue of ,its connection to the tank above the level of the liquid by way of conduit l2. The level'of the liquid or fluid in cavity ll may be observed from either side of the gauge through the slots H and windows 25 and 43.

It is evident that a hydrocarbon fluid under a temperature such, for example, as 1000 F. and a pressure such, for example, as 1000 lbs. Der sq. in. would immediately burst into flame upon contact with the atmosphere containing oxygen. The present construction will therefore find particular utility when utilized in a device for measuring such fluids at these temperatures and pressures, for should the fluid leak from the cavity I 1 past either of the sight glasses 25. it will be trapped in one of the cavities 35 and thus be prevented from being discharged into the atmosphere. Thus the invention provides a means for preventing the contact of the fluid being measured with the atmosphere in the event of failure of the sight glass adjacent the liquid being measured or in the event of leakage around this sight glass.

In use, the valves 54 and 59 may be left open, thus placing the cavities 35 in communication with the atmosphere. Obviously, should leakage occur from the cavity ll into either of the cavities 35, the pressure in these lat er cavities would immediately be raised a substantial amount, which raise would be indicated by the gauge 66, thus calling the attention of the attendant to the fact that leakage was occurring from the primary gaugebody. It is obvious that upon the building up of pressure in the cavities 35, the check valves in the conduits 31 and 38 would be closed, thus preventing discharge of theleaking fluid to the atmosphere and allowing a closing of the valves l5 and IE to disconnect the .entire gauge from the tank with which it isnormally connected. The bell 60 may be electrically connected to the pressure gauge or otherwise made responsive to the pressure of the fluid in cavities 35 to thus audibly advise the attendant of the leakage from the cavity ll;

As brought out before, the invention will find particular utility where fluids, are to be measured having temperatures differing substantially from that of the environment of the gauge or Gauges which have heretofore been built have not been practical foruse in indicating or determining the level of the liquid in hydrogenation apparatus because of sight glass. -Thus the-fluid may: be'extrem'ely cold or extremely hot,"in either of which cases.

from that at which it is desired to;maintain the the fluid to be measured and tend'to maintain the ture.

sight glasses 25 at a desired or suitable 'tempera- Thus if, for exla.mple,' a:iluid at an extremely high temperatureis being measured, a cooling fluid may be introduced into each chamber 35 by virtue ofits respective inlet 38, this conduit in this instance being suitably connected to a source of coolingfluid-(n'ot shown). The cool- I ing fluid will flll the cavities 35 and flow around three sides of the respective sight glasses'25 by virtue of the shoulders 21 which space the'slde and outer walls of these glasses from the walls 28.

Thus while one face of each sight glass will be exposed to the high temperature in chamber i i,

the sight glass will be 'maintained relatively" 1 cool by the circulation of the cooling fluid through the chambers 35. As previously de-' scribed. i1 leakage should occur, pressure would immediately build up in one of the chambers 35 with the result that the check valves in conduits 31 and '38 would be closed. and this building up of pressure would be indicated either by the pressure gauge or by the audible signal.

In measuring certain types of substances, it

frequentlybecome's desirable to'm'odify the tem perature of the gauge in order that an accurate measurement may be obtained. Thus, for example, compounds such as diphenyl have a melting point considerably abovea normal temperature, so that it is generally impossible to meas; ure the level of such a substance in a gauge spaced a substantial distance from the tank which contains the substance; By virtue or the present construction a heating medium maybe admitted to the chambers 35 to thus raise the tem perature of the adiacent gauge parts and to thus maintain the compound being measured in a liq-' uid state whereby an accurate measurement may be obtained.

Where the fluid being measured is under high" I pressure it is apparent that the sight glasses 25 are exposed to this pressure inasmuch as they u back up the mica strips 30. In this event it is.

possible with the construction disclosed to admit a a pressure fluidto each of the recesses or cavities 35. this pressure fluid acting onthe-rear ,face of each of the sight glassesv 25 to thus relieve the same from the strain of the pressure exerted on the face of the sight glassby the fluid in cavity I l. 31 and 38 may or may not be used, if used, these valves being held open by their r spective springs.

In this instance the check valves in the lines It will be apparent that by regulating the supply of pressure fluid a graded pressure may be exerted on the outer face of each sight-glassto act counter to the pressure exerted onthe inner face of. each sight glass.

use of sight glasses formed of fused silica since it provides for the sealing of the cavity without exerting aclamping pressure on the sight glasses-25. Thus'the'transparent members 25 are 05 Still further, by virtue of the mountingof the that a complete cooling of the same may not be efiected by a cooling medium in chambers 35.

In instances where the gauge is utilizedfor measuring fluids at extremely high pressures and extremely high or low temperatures, the pressure fluid supplied to chambers 35 may also be a cooling or heating fluid. Thus the fluid may function not only to exert a counter pressure on the transparent member, but also function to cool or warm the same. If desired, the pressure gauge and audible signal may be eliminated, the attendant in this event observing the discharge from conduit 31 into funnel' 60 to determinewhether or not there is any leakage from the cavity ll. Obviously, if no cooling fluid is supplied to cavities 35, this leakage will be immediately apparent, while if acooling fluid is supplied to cavities 35, the leakage may be observed ifthe fluid being measured differs in appearancefrom the cooling fluid. when the gauge is used inthis manner the check valves might, if desired, be removed and thevalves 54 and 59 adjusted to nearly closed positions in order that discharge from cavities I! will be restrictemthus eliminating danger to the boiler attendants in the event that leakage occurs.

From the above it will be apparent that the invention provides a gauge which may be utilized in measuring the level of fluids at extremely high pressure and also at temperatures diflering substantially from a desired temperature. The gauge is so constructed that failure of the transparent member adjacent the cavity which receives the,

fluid to be measured will not allow a discharge of this fluid into the atmosphere. Further, an attendant will immediately be notifled as to the leakage of the fluid being measured so that the gauge as a unit may be immediately disconnected The right is reserved to make such changes inthe details of construction and arrangement of parts as will fall within thepurview of the attached claims.

What I claim as my invention is:

1. In a gauge-of the class described, a gaug body having a cavity opening through one side thereof for receiving the fluid to be measured, means for sealing the open side of said cavity, means providing a chamber for trapping any fluid escaping from said cavity past said sealing means, and pressure responsive means for .indicating the presence of escaping fluid in said chamber.

2. In a gaugeof the class described, a gauge body having'a cavity opening through one sidethereof for receiving the fluid to be measured, meansfor sealing the open side of said cavity,

atmospheric'pressure, a gauge body having a cavity for receiving the fluid to be measured, a transparent member through which the level of the fluid in the cavity, may be observed, said member being exposed on its one side to the pressure of the fluid in the cavity, and means for exerting a graded regulable pressure on said transparent member acting counter to the pressure exerted on said member by the fluid to be measured to prevent overstrainin'g, of said transparent member.

4. The combination with a gauge for measuring a high temperature and high pressure fluid, and a window member having one face exposed to the high temperature and high pressure of the fluid being measured, of means providing a chamber around the remaining faces of said window member, and means for supplying a cooling-fluid under a graded-reglflable pressure to said chamber. I

5. In a gauge of the class described, a gauge body having a 'cavity for receiving a fluid to be measured, said body being provided with a projection on each side of the cavity extending parallel to and substantially coextensive with the cavity, a cover associated with the body and provided with a recess to receive a sight glass, said cover being further provided'with a groove on each-side of the glass recess but spaced therefrom and of a size to closely receive and engage the side edges of the projections of the body, and means to clamp said body and cover together.

-6. In a gauge of the class described, a gauge body having a cavity for receiving a fluid to be,

measured, a cover for said body having a recess for receiving a sight glass, and a projection on said gauge body snugly 011838631316 in a recess in I said -cover for preventing lateral movement of said body relative to said cover, said projection and said recess being spaced from the cavity in the body and the sightglass receiving recess in the cover.

'I.- In a gauge of the class described, a gauge body having a cavity for receiving a fluid to be measured, a flat sight glass constitutinga closure for one side of said cavity, means providing a chamber partially surrounding said sight glass,

and means for supplying a fluid to said chamber to control the temperature of said sight glass.

8. In a gauge of the class described, a gauge body having a cavity for receiving high temperature fluid to be measured, a flat sight glass through which the level of the fluid in said cavity may be observed, said sight'glass having its rear-face. disposed adjacent one side of said cavity whereby the rear faceof said sight glass is subjected to the temperature of the fluid to be measured in the cavity, and means providing for the flowing of a cooling fluid into contact with the front face and side edges of said sight glass.

fluid to be measured, a cover member for said body member and projections formed on one of said members snugly engaging in recesses in the I other of said members and arranged to prevent temperature of the fluid being measured, means providing a chamber in heat exchange relation with respect to said sight glass, and valve controlled conduits communicating with said chamber providing for the supply of a cooling fluid to and the discharge of the cooling fluid i'rcm said chamber.

HARRY 1:. BRmsFoRn. 

